Wall flumes are vertical conduits attached to the walls of grain bins through which grain can flow. Flumes are thought to encourage funnel flow throughout the height of the bin while reducing the dynamic loads and moments associated with plug flow and side unloading. Discharge outlets from the flume can be placed at any location along the vertical line of the flume. Tests were performed with soft red winter wheat in a smooth-walled, model grain bin 2.44 m in diameter and 7.44 m tall, constructed of galvanized steel. Tests were conducted both with and without the flume. During unloading, the wall flume created an “artificial” funnel flow regime within all parts of the bin which produced wall loads smaller than those measured during filling, other than at the onset of discharge in which a small load spike was observed. However, in unloading through the flume unbalanced wall loads were observed around the circumference of the bin, which produced overturning moments in the plug flow zone. Tests were conducted in which flow was transferred from the wall flume to the center discharge gate. This switch in the discharge position created wall loads significantly larger than those measured during filling at the flume location where the switch occurred. Operator caution should be used in performing these types of flow switches within bins when using wall flumes.